Pen



FIG. 1 is a top-front perspective view of a pen showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left view thereof;

FIG. 5 is a right view thereof;

FIG. 6 is a top-rear perspective view thereof; and,

FIG. 7 is a bottom-front perspective view thereof, wherein since a pen barrel of the pen is combined by two casings, a parting line is shown in FIGS. 1, 4, 5, 6, and 7. 

The ornamental design for a pen, as shown and described. 